The steps to determine which version of the Reflex Student app is currently installed on your iPad vary depending on the version of the iOS running on your iPad. After following the steps below for your specific iPad iOS version simply tap the Reflex Student icon to see the details of the installed version of the app.
iOS 9: Settings / General / Storage and iCloud usage / Storage / Manage Storage
iOS 8: Settings / General / Usage / Manage Storage
iOS 7: Settings / General / Usage